The present invention relates to locking handles for angle cocks and the like, and particularly to spring-loaded locking handles that more effectively maintain the handle in a locked condition in order to prevent accidental operation of the angle cock.
Locking style handles are well-known and widely employed in the railway industry, one example of such use being on angle cocks that are designed for application to the ends of the brake pipe on a railroad car. The cock provides a means for attaching the brake pipe hose via which the respective car brake pipes in a train are connected. Either a ball cock or tapered plug is typically employed for the valve unit, which is normally open to conduct movement of the compressed air in the brake pipe line, and is closed on the end of the brake pipe at the last car of a train. The valve unit is open when the locking handle is parallel to the brake pipe line and is closed when the handle is transverse to the brake pipe line. The handle is designed to lock in both the open and closed positions. In the locked position, rotation of the handle is prevented by interference between locking lugs on the handle and body. In order to operate the valve by rotating the handle, the handle must first be raised slightly to clear the respective locking lugs. This self-locking feature relies on gravity to maintain the handle in its locked position, in which accidental opening or closing of the valve is prevented.
Where specialty type railway cars require unusual runs of the brake pipe, the angle cocks may be situated such that the angle cock must be mounted with the handle disposed sideways, or may even be mounted with the handle on its underside. In such installations, the effect of gravity, particularly when combined with the vibration encountered in railway service, tends to unlock the handle, thereby rendering the angle cock susceptible to accidental opening and closing.